1. Industrial Field of the Invention
This invention relates to a device for realizing visual recognition of nonvisible air flow, and particularly relates to a device for realizing visual recognition of air flow which utilizes especially clean mist that is generated for the purpose of recognizing air flow in a clean room employed for industrial purposes.
2. Prior Art
Known devices for realizing visual recognition of nonvisible air flow are exemplified as follows:
(1) a device which utilizes mosquito-repellent incense smoke;
(2) a device which utilizes smoke generated by a chemical reaction of chemicals such as titanium tetrachloride;
(3) a device which utilizes oil mist generated by heating oil; and
(4) a device which generates pure water mist utilizing pure water as in an ultrasonic humidifier.
However, the aforementioned devices which utilize mosquito-repellent incense, the smoke generated by the chemical reaction of chemicals, and the oil mist encounter following problems: namely, when visual recognition of clean air flow which has been introduced into a clean room for industrial purposes is attempted, not only the clean air is contaminated but also the clean room and machines and equipment in the clean room are contaminated. As a result of this, the manufacturing process for the products which need cleanness is contaminated. Consequently, the aforementioned devices become impossible to be used. Especially, in a case wherein the smoke generated by the chemical reactions of chemicals is utilized, it is dangerous because of their toxicity. In a case wherein the pure water mist is generated, the amount of the mist which can be generated is insufficient. If the sufficient amount of mist is generated, droplets drop to floor surfaces or work tables. Furthermore, the mist generated is eliminated in a short time after being introduced in an air flow, as a result of which, the long-distance visual recognition of the air flow becomes impossible. Furthermore, the mist tends to flow downward because of gravitation, and separate from the air flow, as a result of which, an accurately visual recognition of the air flow becomes impossible.
An object of the present invention is to provide an air flow visualizing device which can overcome the aforementioned problems by introducing clean steam generated by a steam generating device into an insulating chamber in which either one of liquid nitrogen, liquid oxygen, liquefied carbon dioxide, or the like is enclosed for the purpose of generating a misty tracer by rapid cooling. Then the generated misty tracer is directly introduced into an air flow to be visually recognized, or fed out after the temperature of the misty tracer has been controlled so as to be easily captured by the air flow.